An exemplary electro-acoustic stimulation (EAS) device includes 1) a detection facility configured to detect audio content presented to a patient and included in an acoustic stimulation frequency range, 2) an acoustic stimulation management facility configured to direct a loud-speaker to apply acoustic stimulation representative of the audio content included in the acoustic stimulation frequency range to the patient, and 3) an electrical stimulation management facility configured to direct a cochlear implant implanted within the patient to apply sub-threshold electrical stimulation to the patient by way of one or more electrodes disposed within an apical region of a cochlea of the patient together with the application of the acoustic stimulation. Corresponding systems and methods are also disclosed.